What are the causes of engine oil deterioration?
3 Answers
Engine oil deterioration can be caused by filter failure or engine water ingress, as detailed below: Filter Failure: During use, the air filter may wear out or become damaged, allowing external dust to easily enter the crankcase through the cylinder. This increases the viscosity of the engine oil, reducing its lubricating properties. In some cases, it may clog the oil filter, causing the engine to malfunction, leading to damage and shortening its service life. Engine Water Ingress: The most common cause of engine oil deterioration is water contamination, which can turn the oil into an emulsion and disrupt the oil film. When the water content exceeds 0.1%, the antioxidants and detergent dispersants added to the oil become ineffective. If the water content reaches 1% or more, the lubricating properties of the oil deteriorate, and its viscosity decreases. In severe cases, this can lead to mechanical failures such as engine seizure or bearing damage.
As someone who frequently deals with cars, I've found that the main causes of oil deterioration include oxidation issues. When oil is exposed to air for extended periods, it tends to break down and thicken. Additionally, the high-temperature environment during engine operation accelerates the degradation of oil molecules, forming deposits—a common occurrence in urban stop-and-go traffic scenarios. Contamination is another concern to watch for, such as dust or moisture mixing into the oil, especially after driving on dirty roads. This phenomenon worsens when the oil filtration system fails. Mixing oils from different brands may also cause chemical reactions, accelerating deterioration. I've seen cases where owners neglected these factors, resulting in black, viscous oil and increased engine component wear. I recommend regularly checking oil quality and adhering to oil change intervals to prevent soaring overhaul costs.
Over the years of using my car, I've summarized the main reasons for oil deterioration: when the temperature is too high, the oil evaporates and thins, affecting lubrication; contaminants like rainwater or sand particles mix into the oil, which is common after long drives on rural roads; and natural aging over time, especially if the car sits idle, causing the oil additives to lose effectiveness. Once, I forgot to change the oil on time, and as a result, the engine noise increased, and performance dropped significantly—a hard lesson learned. Additionally, driving habits are crucial. For example, frequent short trips prevent the oil from circulating and heating up properly, leading to more carbon buildup. Regular oil changes are essential—don’t skimp to save a few bucks, or you might end up paying hundreds more in repairs.
